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PatchSiren cyber security CVE debrief

CVE-2026-40759 Mikado-Themes CVE debrief

CVE-2026-40759 is a high-severity vulnerability in the Esmée theme, affecting versions up to 1.4. This vulnerability allows unauthenticated attackers to inject PHP objects, potentially leading to arbitrary code execution. The vulnerability has a CVSS score of 8.1, indicating a high level of severity. The CVE was published on 2026-06-17 and last modified on 2026-06-17. Users of the Esmée theme should take immediate action to mitigate this vulnerability.

Vendor
Mikado-Themes
Product
Esmée
CVSS
HIGH 8.1
CISA KEV
Not listed in stored evidence
Original CVE published
2026-06-17
Original CVE updated
2026-06-17
Advisory published
2026-06-17
Advisory updated
2026-06-17

Who should care

Administrators and users of the Esmée theme, particularly those using versions up to 1.4, should be aware of this vulnerability and take necessary precautions to prevent exploitation.

Technical summary

The vulnerability is caused by an unauthenticated PHP object injection in the Esmée theme, affecting versions up to 1.4. This allows attackers to inject malicious PHP objects, potentially leading to arbitrary code execution. The vulnerability has been assigned a CVSS score of 8.1, indicating a high level of severity. The CVSS vector is CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H.

Defensive priority

high

Recommended defensive actions

  • Update the Esmée theme to a version beyond 1.4.
  • Restrict access to the Esmée theme to only trusted users.
  • Implement additional security measures, such as web application firewalls (WAFs) and intrusion detection systems (IDS).
  • Monitor the Esmée theme for any suspicious activity.
  • Consider using a security plugin or service to detect and prevent exploitation attempts.

Evidence notes

The vulnerability was reported by Patchstack and is tracked under CVE-2026-40759. The CVE record and NVD detail can be found at [cve-org] and [nvd], respectively. Additional information can be found at [ref-4].

Sources and references

Verified primary and authoritative sources

  • CVE-2026-40759 CVE Program record

    Publisher, destination, and source semantics verified

    URL: https://www.cve.org/CVERecord?id=CVE-2026-40759

    CVE Program - Official CVE Program record with source-provided CVE metadata.

  • CVE-2026-40759 NVD vulnerability detail

    Publisher, destination, and source semantics verified

    URL: https://nvd.nist.gov/vuln/detail/CVE-2026-40759

    NIST National Vulnerability Database - Official NIST NVD detail page and source-specific vulnerability assessment.

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.